If it seems the sharpies from Redmond are at a turning point, well, they are. Just about two months ago, our Digits blog pointed out that Microsoft was approaching a critical crossroads. With that PC report landing like a blow from a sledgehammer, it appears Microsoft’s been pushed right into the middle of those crossroads.

Spencer Ante stopped by the Markets Hub this morning to discuss what the future holds in store for Microsoft and the rest of the PC ecosystem.

It may seem odd on the face of it for Apple to want to partner up with Yahoo to get more of the latter’s products on the former’s phone. After all, its recent stock slide notwithstanding, Apple is still the coolest kid on the block, and the most profitable, while Yahoo is, well, Yahoo isn’t either. But in the tightly intertwined world of competition and cooperation that is Silicon Valley, these two working together isn’t so odd. It’s all about the “coopetition.”

It’s still just something the two companies are discussing, but the idea is this: Yahoo gets its services and products onto mobile phones and tablets, and Apple gets a services provider that isn’t named Google. Plus, the two don’t really compete that directly in their products and offerings, making for an easier mesh between the two. Spencer Ante stopped by the Markets Hub this morning to break down the possible deal.

Apple, meanwhile, has been looking to partner with companies to help reduce its reliance on Google’s mobile services. Apple’s desire to extract itself from Google runs deep. Apple, which last year ended partnerships with Google over maps and video, has explored breaking up on search for many years and its representatives recently met with companies that have search expertise, people familiar with the matter said.

Facebook is set today (1 p.m. ET) to unveil what’s being called in some quarters the Facebook phone. While it’s not really a phone (at least the indications so far are that it’s not a phone), it is one more brick in the foundation of Facebook’s mobile strategy, which for many is the key growth driver for the company.

“It’s best characterized as an experiment,” Jan Dawson, chief telecoms analyst at research and consultancy firm Ovum said this morning on the Markets Hub. The product likely unveiled today will be basically a Facebook-based homescreen that would replace screen on phones that use Google’s Android operating system, and would have all the social-media site’s features “front and center.”

“It’s going to take over the homescreen,” Dawson said.

“It’s potentially a big deal,” he said. It goes beyond what Facebook’s done previously with mobile, but the real question will be whether or not users actually want this, he said.

Not quite yet, but Yelp Inc. executives may soon be aping that line from Anchorman before they know it. Bigger rivals, most prominently Facebook Inc. last week, are taking aim at Yelp’s business — Yelp’s bread-and-butter business, you might say — of online restaurant reviews.

That could spell trouble for yet another social-media darling.

This week’s selloff, after Facebook unveiled its “graph search” feature, may be a sign that Yelp should find itself a buyer, and fast, Heard on the Street’s Rolfe Winkler said this morning on the Markets Hub.

With the rate at which things change in the tech and mobile world, Yelp could find itself under a serious assault before it knows it. Last week’s selloff was a shot across the bow, so to speak.

BTIG analyst Richard Greenfield cut shares to sell from neutral this morning, saying ”we see a growing tension between the Facebook user experience and monetization.” Essentially, as Facebook works harder to capture ad revenue via mobile devices, the social-networking company is faced with a dilemma: how to maximize ad revenue without annoying users.

Greenfield feels that Facebook is favoring the former at the expense of the latter, and that will create problems down the road.

“While mobile ads perform significantly better than desktop ads, the outperformance is driven by how much of the screen they occupy (more annoying) and ‘fat-fingers’ (accidental clicks),” he says.

SAP Co-CEO Bill McDermott sat down with WSJ deputy managing editor Alan Murray to talk about how the company’s managing through a weak economy, its bet on the euro, the move to mobile and the cloud, and the future of the PC.

For more MarketBeat and other streaming markets coverage from The Wall Street Journal, point your mobile browser to wsj.com/marketspulse.

At least that’s the case in the market today. With Microsoft set to report on Thursday, PC-centric shares are enjoying a remarkably robust session.

Microsoft is up 2.5%, Intel is up 2.4%, Dell is up 3.7%, Applied Micro is up 2% and Micron Technology is up 2.4%. The group is far outpacing the Nasdaq Composite, which is up 0.8%.

Cloud computing and mobile devices like Apple’s iPad have prompted wild talk that the PC world is toast. No doubt, the emerging mobile/cloud world does threaten the PC universe, though Amazon’s recent “cloud” problems raised some eyebrows. But the pace of the PC sector’s demise is being hotly debated, especially after Intel reported blowout earnings last week and promised robust growth up ahead.

Morgan Stanley, in a note this morning, sees PC sales bottoming in the current quarter and it subsequently argues that Microsoft shares, trading at a forward p-e of 10, are “too cheap.” Morgan Stanley rates Microsoft overweight.

BofA Merrill Lynch, which rates Microsoft a buy, says Intel’s report indicates that PC sales may not be as weak as some technology surveys indicate. BofA ML adds that its recent survey of IT buyers found that buyers expect only 4% of current PCs to be replaced by iPads. BofA ML reiterated its “buy” rating.

Morgan Stanley and RBC are doing their best to get the cell-tower stocks moving again, but without much luck.

AT&T’s recently annouced plan to gobble up T-Mobile’s U.S. business in a $39 billion deal sent the cell-tower stocks tumbling. The view: with one less major competitor, demand for more towers to improve mobile operating performance would likely diminish.

That’s still a valid thesis, but analysts like to hunt for bottoms even when the fundamental picture doesn’t shift too much. The usual phrase: the sell-off is overdone!

Morgan Stanley used such reasoning to upgrade American Tower and SBA Communications to overweight from equal weight and affirmed its overweight rating of Crown Castle International Corp. RBC chimed in with similar “bargain-basement” comments, saying that the tower stock valuations “are toward the lower end of historical ranges.”

The double-dose of good feeling is having limited impact in the marketplace, indicating investors aren’t completely convinced. SBA is up a smidge at 38.54, off its 52-week high of 44.44. Crown Castle is down a touch at 40.23, below its 52-week high of 46.27 and American Tower is up marginally at 49.75, shy of its 52-week high of 56.84.

This morning, AT&T is indicated higher, as are a number of other related companies in the wireless/mobile space, including Verizon, Apple, Nokia, Motorola Mobility and BT. Sprint Nextel, which may suffer as the smaller player in a post-deal world, is indicated a touch lower. (Check out our live-blog of the deal conference call.)

The conflict is pushing oil prices higher, with light, sweet crude up about 1% at nearly $103 a barrel on Nymex, according to FactSet. Brent Crude trading in London is up 1.8% at $115.77 a barrel.

Higher energy prices are helping oil companies, with ExxonMobil and Chevron indicated higher at the open. But the conflict in Libya is also feeding worry that conflict could spread or intensify in other oil-producing states.

Lloyds Corporate Markets said earlier today: “It is noteworthy that the UN’s reaction in support of the Libyan anti-government protestors could have wider implications. Similar anti-government sentiments could be possibly expressed more openly now, especially at bigger oil-producing states in the region, with significant implications on oil prices, inflation and possibly global growth.”

Just a quick update from Kaufman Bros. tech analyst Shaw Wu on the latest rumblings over an iPhone for Verizon’s network. He wrote Tuesday:

Our checks indicate that VZ is still excited and hoping to launch iPhone, likely in the [first half of 2011] timeframe, to combat slowing Android momentum in the U.S. and its market share losses to AT&T. Our sources indicate that VZ views iPhone as essential to its future success despite it already carrying a full roster of competing operating systems including Android, BlackBerry, Symbian, Windows, and webOS.

Research in Motion is scheduled to release earnings Thursday and the report is expected to be decent. But the cautious commentary on the shares continues. (See here and here.)

The latest comes from Bernstein Research analyst Pierre Ferragu:

Although we maintain our bearish view on the name, we expect 3Q11 in the high end of guidance. We believe the company delivered well on the quarter as the Torch continued its ramp-up. Although it is too early to see signs of traction with consumers, the Torch attracted Blackberry core users and should have had a positive impact on high-end replacement. We wouldn’t buy into the numbers, though. The stock has performed very strongly in the last 3 months and we expect to see, despite good overall numbers, further signs of weakness on important fundamentals.

But what about all the arguments in RIM’s favor? Their exposure to international markets and those looking for lower-priced handsets. “If growth in international markets and low [average selling price] segments has been a strong support to the business in the last 3 quarters, it is fading away,” wrote Ferragu.

We believe the iPad’s growth margin to be in the region of 30%, with unarguably a much stronger brand premium than Blackberry and probably a much better cost base (lower Qualcom IP rights, better sourcing capabilities, especially for NAND memory). In that context, RIM couldn’t be competitive on that market with more than 10-15% gross margin. If RIM’s plan to make reasonable profits is to sell a 5′ tablet for the price of a 7′ tablet… it doesn’t sound like a sustainable competitive advantage. QNX isn’t likely to change RIM’s fate in the medium term. If the platform could potentially enhance Blackberry products, we believe it would take time before it changes the current well documented lack of excitement of established Blackberry users.

Despite all the recent gloominess being expressed by analysts about Research in Motion, the shares seem to be hanging in there. They’re still above the 200-day simple moving average, a key gauge of momentum. Since the end of September Research in Motion is up 28.5%. Year-to-date, however, they’re down about 8%.

Except for Minnesotans such as Dave Kansas, it’s pretty hard for most people to get riled up about earnings from Minnesota Mining & Manufacturing, or 3M.

Sure, it’s a Dow Component. And as a conglomerate with tentacles stretching throughout the economy, it’s a helpful bellwether. But you know, scotch tape doesn’t exactly get the those animal spirits growling.

But wait, there’s one division of 3M that’s a direct tie to the company everyone loves to love, Apple. Citigroup analysts note that 3M makes the touch screen films for the best-selling Apple iPad screen as well as the Apple iPhone.

According to transcripts from a recent earnings call, that sexy tidbit of 3M’s broad portfolio is buried in the company’s retro-sounding “electro and communications” division, which happened to surge like crazy in the quarter 3M reported this morning. Sales in that division jumped 24%. The company doesn’t mention Apple by name, which isn’t surprising given Jobs & Co.’s fanatical focus on secrecy.

In its press release 3M cited “continued strength in businesses that serve the consumer electronics industry; local-currency sales up over 50 percent in electronics markets materials and 30 percent in the electronic solutions business.” The division posted a quarterly operating profit of $173 million, up 49% from the same period last year. Not bad for a staid old industrial conglomerate.

BlackBerry maker Research In Motion Ltd. unveiled its first tablet computer and a new operating system that will power it, joining the race to catch up with Apple Inc.’s iPad. Investors don’t seem to be ebullient on RIM’s prospects, shares are down about 1% premarket. Here’s how some analysts see it.

Stifel Nicolaus: Generally we were pleasantly surprised by the PlayBook specs. At a time when RIM has been widely criticized for falling behind on the innovation curve relative to its smartphone peers, the new tablet appears to put RIM back on the leading edge of technology.

Cowen and Company: Pricing was not disclosed, but we believe the lack of mobile voice/data support will limit operator interest in (and subsidy dollars for) the initial PlayBook, perhaps stunting early developer support and end-user adoption.

Morgan Stanley: We believe the PlayBook is well suited for enterprise, but could be far less successful with consumers. Between the crowded tablet market, the potential for a major OS overhaul across the entire platform with all the risks that entails, and the continued share loss in North America in both device shipments and subscribers, we remain Underweight.

Goldman Sachs: RIM’s PlayBook tablet surprised us by being positioned for the enterprise, rather than the consumer, and by having a robust set of specs including a dual-core 1GHz processor and 2 HD cameras. This could allow RIM to offer a differentiated product rather than a “me too” to the iPad. The PlayBook offers a unique use case by tethering to the BlackBerry over Wi-Fi or Bluetooth as a secure extension to the BlackBerry in the enterprise that can serve as a display or a projector. While the Wi-Fi tethering eliminates the expense of a separate data plan, it also reduces the incentive for carrier subsidies. In addition, the Q1 launch is a qtr behind expectations.

Deutsche Bank: At the start of their developer conference, RIM announced a new device called the PlayBook, their take on the tablet. The device is set to ship in [first quarter of 2011], missing the Holiday Shopping Season. Our first impression is the device is comparable to all the other tablets coming on the market, but runs a new proprietary RIM OS.

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If Iran reaches a nuclear deal, Western investors will almost certainly queue up to invest in the country. The first stop for much of that money, at least initially, could be the Tehran Stock Exchange.